Microsurgical dissection of the carpal tunnel with respect to neurovascular structures at risk during endoscopic carpal tunnel release

Carpal Tunnel Anthropometrics Using Acrylic Casts: A Cadaveric Study With Implications for Carpal Tunnel Release

BACKGROUND

Abundant literature exists on the morphology of the carpal tunnel. Despite this, the shape of the carpal tunnel has been reported erratically, and most studies did not attempt to correlate findings with measurements taken from cadavers. The objective of this study was to perform a morphological analysis, determine the shape and mean dimensions of the carpal tunnel, determine the level of the narrowest area of the tunnel, and establish a set of values capable of serving as a reference for carpal tunnel release.

METHODS

The carpal tunnels of 20 fresh cadaveric hands were dissected, and acrylic casts were created and measured using industrial computed tomography.

RESULTS

Of the 20 casts, 19 were shaped like elliptic cylinders, with little variation in their measurements along the length. The location of the narrowest section of the carpal tunnel is very different among casts, and the length of the roof of the carpal tunnel ranged from 21.26 to 29.86 mm.

CONCLUSIONS

The most common shape of the carpal tunnel is an elliptic cylinder. Because of the unpredictability of the location of the narrowest area of the carpal tunnel, carpal tunnel release must continue through all extension of its roof. We advise that the release should rarely be extended distally more than 30 mm from the distal palmar wrist crease, which corresponds, in most cases, to the middle of the pisiform.

State of the art review. Complications after carpal tunnel release

Carpal tunnel release (CTR) is the most performed surgery of the upper extremity. It is effective but not without complications. This state-of-the-art review covers most common intra- and postoperative complications after CTR. As endoscopic carpal tunnel release (ECTR) has developed over time, severe complications, such as nerve lesions, have diminished. ECTR still has a higher risk on transient nerve lesions. Open CTR on the other hand has a higher incidence of wound-related problems, including scar tenderness, irrespective of incision used. Most complications, such as pillar pain and infection, are ill-defined in the literature, leaving the exact incidence unknown and proposing challenges in treatment. The same is true for failure of treatment. Optimizing the length and location of incisions has played a vital role in reducing intra- and postoperative complications in CTR. It is expected that technical advances, such as ultrasound-guided percutaneous carpal tunnel release, will continue to play a role in the future.Level of evidence: V.

Anatomical considerations of US-guided carpal tunnel release in daily clinical practice

Carpal tunnel syndrome is the most frequent compression neuropathy with an incidence of one to three subjects per thousand. As specific anatomical variations might lead to unintended damage during surgical interventions, we present a review to elucidate the anatomical variability of the carpal tunnel region with important considerations for daily clinical practice: several variants of the median nerve branches in and around the transverse carpal ligament are typical and must - similarly to the variant courses of the median artery, which may be found eccentric ulnar to the median nerve - be taken into account in any interventional therapy at the carpal tunnel. Unintended interference in these structures might lead to heavy arterial bleeding and, in consequence, even underperfusion of segments of the median nerve or, if neural structures such as variant nerve branches are impaired or even cut, severe pain-syndromes with a profound impact on the quality of life. This knowledge is thus crucial for outcome- and safety-optimization of different surgical procedures at the volar aspect of the wrist and surgical therapy of the carpal tunnel syndrome e.g., US-guided carpal tunnel release, as injury might result in dysfunction and/or pain on wrist motion or direct impact in the region concerned. For most variations, anatomical and surgical descriptions vary, as official classifications are still lacking.

The Reliability of Kaplan's Cardinal Line as a Potential Surface Marker for the Superficial Palmar Arch During Carpal Tunnel Release: An Anatomical Study With Surgical Perspective

Purpose Kaplan's cardinal line (KCL) provides a more accurate reference point to the superficial palmar arch (SPA). The aim was to determine the KCL-SPA distances and their relationship with the other defined superficial landmarks, such as distal wrist crease (DWC) or distal portion of the transverse carpal ligament (TCL) or DWC-TCL distance. The objective was to determine the distal limit of the incision made during carpal tunnel release (CTR). Methods Sixty hands were dissected after KCL was drawn on each hand using standard methods. The distance from KCL to the SPA was measured along the radial and ulnar borders of the ring finger and recorded as radial and ulnar KCL-SPA distance, respectively. The distance between the DWC and the distal portion of the TCL was also measured (DWC-TCL). Correlation analysis was done between the DWC-TCL and KCL-SPA distance. The ratios between the radial and ulnar KCL-SPA distance and DWC-TCL distance were calculated and mentioned as radial and ulnar Kaplan cardinal index, respectively. Results KCL-SPA distance was 6.8±3.7 mm along the radial border and 6.6±3.6 mm along the ulnar border of the ring finger. The DWC-TCL distance was 29.4±1.2 mm. The means of radial and ulnar Kaplan cardinal indices were 0.23 and 0.22, respectively. A significant correlation was found between the DWC-TCL distance and the KCL-SPA distances. Conclusion Clinically, KCL can be appraised as a predictable surface landmark in limiting the distal-most extent of the incision during CTR and protecting SPA from transection. The SPA was found to lie at a variable distance from the KCL, and the minimum distance was found to be 3.3 mm. This should be considered as the maximum permissible extension of CTR incision beyond KCL.

An Incision-less Ultrasound-guided Carpal Tunnel Release Technique

Ultrasound guidance in the operative treatment of carpal tunnel syndrome is gaining in popularity as it noninvasively provides the surgeon with a real-time high-resolution overview of anatomic structures. A new incision-less approach to achieve a division of the transverse carpal ligament has been developed that combines ultrasound guidance with cannulated needles and a thread. Conceptually, an abrasive thread is looped percutaneously around the ligament while avoiding injury to neurovascular structures, the palmar aponeurosis, and skin. The thread is positioned using 2 puncture sites and a contoured Tuohy needle under ultrasound visualization. With a minimal injury to surrounding structures, this approach is designed to minimize recovery time and decrease pillar pain. This article will provide a step-by-step overview of the technique and includes a review of clinical outcomes published so far.

'INSIGHT-PRECISION': a new, mini-invasive technique for the surgical treatment of carpal tunnel syndrome

Objective

To describe a new mini-invasive surgical technique for carpal tunnel release and to present clinical findings associated with using this technique.

Methods

Patients with idiopathic carpal tunnel syndrome without prior surgical treatment, who underwent a new minimally-invasive surgical technique using a specific surgical tool-kit developed by the author, were included. Prospective data were collected, including preoperative electrodiagnostic testing. The subjective condition of all patients was evaluated pre- and postoperatively with a five-level Likert-type scale (LS) and muscular strength was tested using a JAMAR dynamometer and pinch gauge.

Results

A total of 116 patients (157 hands/cases) underwent surgery performed by the author, and were followed for a mean of 40 months (range, 6 months–7 years). Of these, preoperative electrodiagnostic testing was performed in 112 patients (96.6%). No significant complications were reported. By three months, patients reported that they were satisfied or very satisfied in 147/149 cases (98.7%; LS grade I and II). Strength recovery at three months, based on the average of four measures, was 99.17% (range, 97.43–100.97%).

Conclusions

The described technique is minimally invasive, safe and simple to perform, and provides good results.

Functional Outcomes of 300 Carpal Tunnel Release: 1.5 cm Longitudinal Mini-incision

Objective

There is an opportunity for median nerve decompression by open surgery in carpal tunnel syndrome which is the most common surgical procedure in neurosurgical practice. The aim of this study is to evaluate the long-term outcomes of carpal tunnel release with 1.5 cm longitudinal mini-incision technique with regarding the effectiveness and safety.

Methods

For this prospective study, 300 hands for 188 patients with advanced carpal tunnel syndrome who had indication for neurolysis underwent carpal tunnel release through a 1.5 cm longitudinal mini-incision between March 2011 and 2015. There were 132 (70%) females and 56 (30%) males with a mean age of 40 ± 29.5 years (ranging from 24 to 73) and female to male: About 2.56.178 operations were performed for the right hand and 122 for the left hand. Preoperatively, all patients were evaluated with clinical examination and nerve conduction studies. The clinical effects of the patients assessed with the Global Symptom Score (GSS) and Visual Analog Patient Satisfaction Scale.

Results

The mean follow-up period was 18.6 ± 9.3 months (12-30 months). Postoperatively, 2% (six hands) complained of residual mild pain with tenderness of scar and only 1% (three hands) complained of median nerve damage (neuropraxy) with tingling and numbness but was temporary which improved after 1 week. Five patients (seven hands) loosed strength of their wrists, but muscle force of abductor pollicis brevis reinforced after 1 month. There is no evidence of local infection, stiffness, loss of some wrist strength, or recurrence of the disorder. Postoperative GSS scoring obviously improved than preoperative (P < 0.002). There is no patient who underwent reoperation. The mean time recovery appeared almost 2 weeks.

Conclusion

1.5 cm longitudinal mini-incision method in carpal tunnel syndrome decompression showed satisfactory pain relief, wound healing, and nontender scar with good functional outcomes. The technique was performed safely without major complication.

Anatomic Relationship Between the Hook of the Hamate and the Distal Transverse Carpal Ligament: Implications for Ultrasound-Guided Carpal Tunnel Release

OBJECTIVE

During ultrasound-guided carpal tunnel release, osseous landmarks may supplement direct visualization of the distal transverse carpal ligament (dTCL) to ensure a complete release. The purpose of this study was to determine the relationship between the apex of the hook of the hamate (aHH) and the dTCL within the transverse safe zone (TSZ) of the carpal tunnel.

DESIGN

Twenty unembalmed cadaveric specimens were dissected to determine the aHH-dTCL distance and the aHH-SPA distance (the distance between the aHH and the superficial palmar arch) at the ulnar and radial limits of the TSZ (the distance between the hook of the hamate or ulnar artery to the median nerve).

RESULTS

The aHH-dTCL distance averaged 11-12 mm across the TSZ (maximum, 18.2 mm), whereas the aHH-SPA distance was significantly greater on the radial side of the TSZ compared with the ulnar side (22.6 ± 3.6 mm vs. 14.0 ± 4.0 mm).

CONCLUSIONS

The dTCL lies approximately 11-12 mm distal to the aHH across the TSZ, with an upper limit of 18.2 mm. Along with direct sonographic visualization of the dTCL, the aHH can be used with other osseous landmarks to estimate the position of the dTCL during ultrasound-guided carpal tunnel release.

Sonographic Visualization of Thenar Motor Branch of the Median Nerve: A Cadaveric Validation Study

BACKGROUND

The thenar motor branch (TMB) of the median nerve may be affected in carpal tunnel syndrome and can be injured during carpal tunnel surgery. Although ultrasound has been used to identify small nerves throughout the body, the sonographic evaluation of the TMB has not been investigated formally.

OBJECTIVE

To document the ability of ultrasound to visualize the TMB of the median nerve in an unembalmed cadaveric model.

DESIGN

Prospective laboratory investigation.

SETTING

Procedural skills laboratory at a tertiary medical center.

METHODS

On the basis of anatomical descriptions, dissection and clinical experience, a technique was developed to sonographically identify the presumed TMB of the median nerve at the distal carpal tunnel. A single, experienced examiner then identified the presumed TMB in 10 unembalmed, cadaveric upper limb specimens (4 right, 6 left) obtained from 9 donors (4 male, 5 female) ages 76-85 years with body mass indices of 18.2-29.5 kg/m² with both 12-3 MHZ and 16-7 MHz linear array transducers. The same examiner then injected 0.2-0.3 mL of diluted colored latex into and around the presumed TMB using direct ultrasound guidance. At a minimum of 24 hours postinjection, specimens were dissected under loupe magnification to determine the location of the latex injectate.

MAIN OUTCOME MEASURE

The location of latex injectate relative to the anatomically identified TMB.

RESULTS

A vertical, linear, hypoechogenic region was sonographically identified arising from the median nerve at the distal carpal tunnel in all 10 specimens and was hypothesized to represent the vertical segment of the TMB. Both transducers allowed identification of the TMB, although localization was subjectively facilitated by the higher frequency transducer. All 10 sonographically guided injections placed latex into and around the TMB of the median nerve, confirming that ultrasound had accurately identified the TMB.

CONCLUSIONS

Sonographic evaluation of the TMB of the median nerve is technically feasible and should be considered when clinically indicated. Further research and clinical experience is necessary to define the role of sonographic TMB imaging in the evaluation and management of patients with carpal tunnel syndrome.

LEVEL OF EVIDENCE

IV.

Endoscopic and Open Release Similarly Safe for the Treatment of Carpal Tunnel Syndrome. A Systematic Review and Meta-Analysis

BACKGROUND

The Endoscopic Release of Carpal Tunnel Syndrome (ECTR) is a minimal invasive approach for the treatment of Carpal Tunnel Syndrome. There is scepticism regarding the safety of this technique, based on the assumption that this is a rather "blind" procedure and on the high number of severe complications that have been reported in the literature.

PURPOSE

To evaluate whether there is evidence supporting a higher risk after ECTR in comparison to the conventional open release.

METHODS

We searched MEDLINE (January 1966 to November 2013), EMBASE (January 1980 to November 2013), the Cochrane Neuromuscular Disease Group Specialized Register (November 2013) and CENTRAL (2013, issue 11 in The Cochrane Library). We hand-searched reference lists of included studies. We included all randomized or quasi-randomized controlled trials (e.g. study using alternation, date of birth, or case record number) that compare any ECTR with any OCTR technique. Safety was assessed by the incidence of major, minor and total number of complications, recurrences, and re-operations.The total time needed before return to work or to return to daily activities was also assessed. We synthesized data using a random-effects meta-analysis in STATA. We conducted a sensitivity analysis for rare events using binomial likelihood. We judged the conclusiveness of meta-analysis calculating the conditional power of meta-analysis.

CONCLUSIONS

ECTR is associated with less time off work or with daily activities. The assessment of major complications, reoperations and recurrence of symptoms does not favor either of the interventions. There is an uncertain advantage of ECTR with respect to total minor complications (more transient paresthesia but fewer skin-related complications). Future studies are unlikely to alter these findings because of the rarity of the outcome. The effect of a learning curve might be responsible for reduced recurrences and reoperations with ECTR in studies that are more recent, although formal statistical analysis failed to provide evidence for such an association.

LEVEL OF EVIDENCE

I.

Endoscopic and Open Release Similarly Safe for the Treatment of Carpal Tunnel Syndrome. A Systematic Review and Meta-Analysis

Background

The Endoscopic Release of Carpal Tunnel Syndrome (ECTR) is a minimal invasive approach for the treatment of Carpal Tunnel Syndrome. There is scepticism regarding the safety of this technique, based on the assumption that this is a rather “blind” procedure and on the high number of severe complications that have been reported in the literature.

Purpose

To evaluate whether there is evidence supporting a higher risk after ECTR in comparison to the conventional open release.

Methods

We searched MEDLINE (January 1966 to November 2013), EMBASE (January 1980 to November 2013), the Cochrane Neuromuscular Disease Group Specialized Register (November 2013) and CENTRAL (2013, issue 11 in The Cochrane Library). We hand-searched reference lists of included studies. We included all randomized or quasi-randomized controlled trials (e.g. study using alternation, date of birth, or case record number) that compare any ECTR with any OCTR technique. Safety was assessed by the incidence of major, minor and total number of complications, recurrences, and re-operations.The total time needed before return to work or to return to daily activities was also assessed. We synthesized data using a random-effects meta-analysis in STATA. We conducted a sensitivity analysis for rare events using binomial likelihood. We judged the conclusiveness of meta-analysis calculating the conditional power of meta-analysis.

Conclusions

ECTR is associated with less time off work or with daily activities. The assessment of major complications, reoperations and recurrence of symptoms does not favor either of the interventions. There is an uncertain advantage of ECTR with respect to total minor complications (more transient paresthesia but fewer skin-related complications). Future studies are unlikely to alter these findings because of the rarity of the outcome. The effect of a learning curve might be responsible for reduced recurrences and reoperations with ECTR in studies that are more recent, although formal statistical analysis failed to provide evidence for such an association. Level of evidence: I.

A handy review of carpal tunnel syndrome: From anatomy to diagnosis and treatment

Carpal tunnel syndrome (CTS) is the most commonly diagnosed disabling condition of the upper extremities. It is the most commonly known and prevalent type of peripheral entrapment neuropathy that accounts for about 90% of all entrapment neuropathies. This review aims to provide an outline of CTS by considering anatomy, pathophysiology, clinical manifestation, diagnostic modalities and management of this common condition, with an emphasis on the diagnostic imaging evaluation.

Endoscopic release for carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is the most common compressive neuropathy of the upper extremity. It is caused by increased pressure on the median nerve between the transverse carpal ligament and the carpal bones. Surgical treatment consists of the release of the nerve by cutting the transverse carpal ligament. This can be done either with an open approach or endoscopically.

OBJECTIVES

To assess the effectiveness and safety of the endoscopic techniques of carpal tunnel release compared to any other surgical intervention for the treatment of CTS. More specifically, to evaluate the relative impact of endoscopic techniques in relieving symptoms, producing functional recovery (return to work and return to daily activities) and reducing complication rates.

SEARCH METHODS

This review fully incorporates the results of searches conducted up to 5 November 2012, when we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE and EMBASE. There were no language restrictions. We reviewed the reference lists of relevant articles and contacted trial authors. We also searched trial registers for ongoing trials. We performed a preliminary screen of searches to November 2013 to identify any additional recent publications.

SELECTION CRITERIA

We included any randomised controlled trials (RCTs) and quasi-RCTs comparing endoscopic carpal tunnel release (ECTR) with any other surgical intervention for the treatment of CTS.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration.

MAIN RESULTS

Twenty-eight studies (2586 hands) were included. Twenty-three studies compared ECTR to standard open carpal tunnel release (OCTR), five studies compared ECTR with OCTR using a modified incision, and two studies used a three-arm design to compare ECTR, standard OCTR and modified OCTR.At short-term follow-up (three months or less), only one study provided data for overall improvement. We found no differences on the Symptom Severity Scale (SSS) (scale zero to five) (five studies, standardised mean difference (SMD) -0.13, 95% CI -0.47 to 0.21) or on the Functional Status Scale (FSS) (scale zero to five) (five studies, SMD -0.23, 95% CI -0.60 to 0.14) within three months postoperatively between ECTR and OCTR. Pain scores favoured ECTR over conventional OCTR (two studies, SMD -0.41, 95% CI -0.65 to -0.18). No difference was found between ECTR and OCTR (standard and modified) when pain was assessed on non-continuous dichotomous scales (five studies, RR 0.69, 95% CI 0.33 to 1.45). Also, no difference was found in numbness (five studies, RR 1.14; 95% CI 0.76 to 1.71). Grip strength was increased after ECTR when compared with OCTR (six studies, SMD 0.36, 95% CI 0.09 to 0.63). This corresponds to a mean difference (MD) of 4 kg (95% CI 1 to 6.9 kg) when compared with OCTR, which is probably not clinically significant.In the long term (more than three months postoperatively) there was no significant difference in overall improvement between ECTR and OCTR (four studies, RR 1.04, 95% CI 0.95 to 1.14). SSS and FSS were also similar in both treatment groups (two studies, MD 0.02, 95% CI -0.18 to 0.22 for SSS and MD 0.01, 95% CI -0.14 to 0.16 for FSS). ECTR and OCTR did not differ in the long term in pain (six studies, RR 0.88, 95% CI 0.57 to 1.38) or in numbness (four studies, RR 0.64, 95% CI 0.31 to 1.35). Results from grip strength testing favoured ECTR (two studies, SMD 1.13, 95% CI 0.56 to 1.71), corresponding to an MD of 11 kg (95% CI 6.2 to 18.81). Participants treated with ECTR returned to work or daily activities eight days earlier than participants treated with OCTR (four studies, MD -8.10 days, 95% CI -14.28 to -1.92 days).Both treatments were equally safe with only a few reports of major complications (mainly with complex regional pain syndrome) (15 studies, RR 1.00, 95% CI 0.38 to 2.64).ECTR resulted in a significantly lower rate of minor complications (18 studies, RR 0.55, 95% CI 0.38 to 0.81), corresponding to a 45% relative drop in the probability of complications (95% CI 62% to 19%). ECTR more frequently resulted in transient nerve problems (ie, neurapraxia, numbness, and paraesthesiae), while OCTR had more wound problems (ie, infection, hypertrophic scarring, and scar tenderness). ECTR was safer than OCTR when the total number of complications were assessed (20 studies, RR 0.60, 95% CI 0.40 to 90) representing a relative drop in the probability by 40% (95% CI 60% to 10%).Rates of recurrence of symptoms and the need for repeated surgery were comparable between ECTR and OCTR groups.The overall risk of bias in studies that contribute data to these results is rather high; fewer than 25% of the included studies had adequate allocation concealment, generation of allocation sequence or blinding of the outcome assessor.The quality of evidence in this review may be considered as generally low. Five of the studies were presented only as abstracts, with insufficient information to judge their risk of bias. In selection bias, attrition bias or other bias (baseline differences and financial conflict of interest) we could not reach a safe judgement regarding a high or low risk of bias. Blinding of participants is impossible due to the nature of interventions.We identified three further potentially eligible studies upon updating searches just prior to publication. These compared ECTR with OCTR (two studies) or mini-open carpal tunnel release (one study) and will be fully assessed when we update the review.

AUTHORS' CONCLUSIONS

In this review, with support from low quality evidence only, OCTR and ECTR for carpal tunnel release are about as effective as each other in relieving symptoms and improving functional status, although there may be a functionally significant benefit of ECTR over OCTR in improvement in grip strength. ECTR appears to be associated with fewer minor complications compared to OCTR, but we found no difference in the rates of major complications. Return to work is faster after endoscopic release, by eight days on average. Conclusions from this review are limited by the high risk of bias, statistical imprecision and inconsistency in the included studies.

The carpal insertions of the transverse carpal ligament

PURPOSE

To quantitatively define the anatomic insertions of the transverse carpal ligament (TCL) to the carpals.

METHODS

We dissected 5 fresh-frozen cadaver limbs, isolating the TCL. The ligament insertion sites into bone were clearly marked and photographed. We then used computer software to measure the area of insertion into the individual carpals.

RESULTS

The TCL had consistent insertion sites into the scaphoid, trapezium, pisiform, and hamate. The average insertion of the TCL on the scaphoid was 6 × 6 mm (proximal to distal × radial to ulnar maximum distance), trapezium 13 × 6 mm, pisiform 9 × 6 mm, and hamate 11 × 5 mm. The area of ligament insertion on the scaphoid was 29 mm(2), trapezium was 42 mm(2), pisiform was 38 mm(2), and hamate was 40 mm(2). The perimeter of the ligament insertion on the scaphoid was 21 mm, trapezium was 28 mm, pisiform was 25 mm, and hamate was 29 mm.

CONCLUSIONS

The TCL has a broad but definable footprint on the trapezium and scaphoid on the radial side and the hamate and the pisiform on the ulnar side of the carpal tunnel. The distal carpal insertion sites are longer and oblong, whereas the proximal insertion sites are more circular.

CLINICAL RELEVANCE

Precise knowledge of TCL attachment sites may allow the surgeon greater confidence and safety during procedures that involve its release, such as carpal tunnel release, trapeziectomy, hook of hamate excision, or Guyon canal release.

Ultra-minimally invasive sonographically guided carpal tunnel release: anatomic study of a new technique

OBJECTIVES

The purposes of this study were to measure a safe zone and a path for ultra-minimally invasive sonographically guided carpal tunnel release with a 1-mm incision in healthy volunteers and then test the procedure in cadavers.

METHODS

First, a previously reported sonographic zone was defined as the space between the median nerve and the closest ulnar vascular structure. Axially, the safest theoretical cutting point for carpal tunnel release was set by bisecting this zone. Magnetic resonance imaging was used for axially determining the limits of the sectors (origin at the cutting point) that did not enclose structures at risk (arteries and nerves) and coronally for determining whether our release path could require directions that could potentially compromise safety (origin at the pisiform's proximal pole). Second, in cadavers, we performed ultra-minimally invasive sonographically guided carpal tunnel release from an intracarpal position through a 1-mm antebrachial approach. Efficacy (deepest fibrous layer release rate), safety (absence of neurovascular or tendon injury), and damage to any anatomy superficial to transverse carpal ligament were assessed by dissection.

RESULTS

All 11 of our volunteers (22 wrists) had safe axial sectors located volar and radially of at least 80.4º (considered safe). Release path directions were theoretically safe (almost parallel to the longitudinal axis of the forearm). In 10 cadaver wrists, ultra-minimally invasive sonographically guided carpal tunnel release was effective (100% release rate) and safe without signs of intrusion into the superficial anatomy.

CONCLUSIONS

Ultra-minimally invasive sonographically guided carpal tunnel release in a safe sonographic zone may be feasible The technique preserves the superficial anatomy and diminishes the damage of a surgical approach.

Surgical anatomy of the Guyon canal in children

OBJECT

The anatomy of the Guyon canal is crucial for open and endoscopic surgeries for ulnar canal syndrome at the wrist level. It is also of interest for surgical treatment of carpal canal syndromes. Whereas the Guyon canal is largely described in adults, no studies exist in children. In the present study, the authors examined the Guyon canal in children.

METHODS

Sectional anatomy was used. Thirty-two formalin-fixed cadavers (64 sides) were examined (age range 2-11 years). The hands were transversely cut into 2-3-mm-thick slices. Slices were placed in embedding medium, and transverse sections (10 μm thick) were stained with histological methods and photographed under a light microscope.

RESULTS

The roof of the Guyon canal was attached to the flexor retinaculum laterally to the hamulus of the hamate bone. Thus, the radial boundary of the Guyon canal was lateral to the hamulus, which became part of the floor of the Guyon canal. An ulnar neurovascular bundle was found directly volar to the hamulus in 93.8% of the cases and slightly medial to the hamulus (to the ulnar side) in 6.2% of the cases. Proximally, the ulnar artery and nerve were sustained by the flexor retinaculum in direct apposition to the carpal canal.

CONCLUSIONS

In children, the Guyon canal displays an anatomical particularity regarding the topography of the ulnar artery and nerve that may be of relevance for intraoperative orientation and endoscopic navigation to avoid lesions to the ulnar nerve and artery in carpal and Guyon canal syndromes.

The Clinical Application of Kaplan's Cardinal Line as a Surface Marker for the Superficial Palmar Arch

We feel the original description of Kaplan's cardinal line provides a more accurate reference point to the superficial palmar arterial arch. We sought to anatomically correlate the relationship of Kaplan's cardinal line to the superficial palmar arch. Sixty hands (30 cadavers) were dissected after Kaplan's original description was drawn on each hand. Measurements we made from Kaplan's cardinal line to the superficial palmar arch at both the radial and ulnar borders of the ring finger. The superficial palmar arterial arch was an average of 10.4 and 11.8 mm from the radial and ulnar borders of the ring finger with standard deviations of roughly 4 mm for each measurement. Clinically, Kaplan's cardinal line is a more predictable landmark for the superficial palmar arch. In referencing this landmark as the distal most extent of an open or endoscopic carpal tunnel release, the superficial palmar arch should be free of transection.

Single portal endoscopic carpal tunnel release: modification of Menon's technique and data from 65 cases

The purpose of our study is to make a follow-up evaluation of endoscopic carpal tunnel release under focal anesthesia using the Wolf single portal system. A total of 65 patients with a mean age of 50 years undergoing 79 procedures were retrospectively studied. Preoperative complaints, intraoperative findings, and postoperative results of all the patients were recorded. Follow-up was conducted at 1, 5, 12, and 24 weeks and at 1 year postoperatively. Wound pain, analysis of satisfaction, Levine functional status scales, and surgical complications were included. No patients sustained iatrogenic neurovascular injury or hematoma formation. The average Levine functional severity score decreased from 2.82 points preoperatively to 1.2 points at the most recent survey. One case recurred at 1 year after the surgery and subsequently underwent open release. Surgery using the Wolf single portal system under focal anesthesia is a safe and efficacious option for endoscopic carpal tunnel release.

Endoscopic versus open carpal tunnel release

PURPOSE

This study compared endoscopic carpal tunnel release with the conventional open technique with respect to short- and long-term improvements in functional and clinical outcomes.

METHODS

We assessed 72 outpatients diagnosed with carpal tunnel syndrome. Of these patients, 37 underwent the endoscopic method according to Chow and 35 were assigned to the open method. Improvement in symptoms, severity, and functionality were evaluated at 2 days, 1 week, 2 weeks, and 1 year postoperatively. Changes in clinical outcomes were evaluated at 1 year postoperatively. Complications were also assessed.

RESULTS

Both groups showed similar improvement in all but 1 outcome 1 year after the release; increase in grip strength was significantly higher in the endoscopic group. However, the endoscopic method showed a greater improvement in symptoms and functional status compared with the open method at 2 days, 1 week, and 2 weeks postoperatively. Separate analysis of the questions referring to pain showed that the delay in improvement in the open group was because of the persistence of pain for a longer period. Paresthesias and numbness decrease immediately after the operation with comparable rates for both groups.

CONCLUSIONS

Endoscopic carpal tunnel release provides a faster recovery to operated patients for the first 2 weeks, with faster relief of pain and faster improvement in functional abilities. Paresthesia and numbness subside in an identical manner with the 2 techniques. At 1 year postoperatively, both open and endoscopic techniques seem to be equivalently efficient.

Carpal tunnel syndrome--a comprehensive review

PURPOSE

To provide a comprehensive review of the management of carpal tunnel syndrome.

METHODS AND RESULTS

A systematic literature review is provided of the history, anatomy, pathophysiology, epidemiology, diagnostic criteria, investigative surgical techniques, results and complications for carpal tunnel syndrome.

CONCLUSION

Surgery for carpal tunnel syndrome requires meticulous attention to history-taking, investigation, counseling, training and surgical technique if unsatisfactory results and complications are to be avoided.